Decide on your topic and write down:
a) what you already know about it
b) what you would like to know about it
For ideas:
https://en.wikipedia.org/wiki/List_of_tallest_buildings_in_the_United_States
https://en.wikipedia.org/wiki/Sydney_Opera_House
https://en.wikipedia.org/wiki/Parliament_House,_Canberra
https://en.wikipedia.org/wiki/Sydney_Harbour_Bridge
https://en.wikipedia.org/wiki/Royal_Exhibition_Building
https://en.wikipedia.org/wiki/Canterbury_Cathedral
https://en.wikipedia.org/wiki/Windsor_Castle
https://en.wikipedia.org/wiki/London_Eye
https://en.wikipedia.org/wiki/Wembley_Stadium
https://en.wikipedia.org/wiki/Victoria_Tower
https://en.wikipedia.org/wiki/History_of_the_United_States
https://en.wikipedia.org/wiki/History_of_the_British_Isles
https://en.wikipedia.org/wiki/History_of_Australia
https://en.wikipedia.org/wiki/History_of_Canada
https://en.wikipedia.org/wiki/Attack_on_Pearl_Harbor
https://en.wikipedia.org/wiki/Slavery_in_the_United_States
https://en.wikipedia.org/wiki/List_of_national_parks_of_the_United_States
https://en.wikipedia.org/wiki/Coal_mining_in_the_United_Kingdom
https://en.wikipedia.org/wiki/Tudor_period
https://en.wikipedia.org/wiki/British_Empire
https://en.wikipedia.org/wiki/Independence_Day_(United_States)